jlb@aipna.ed.ac.uk (John Beaven) (11/21/89)
Hi folks. I have recently got hold of a cheap monochrome VGA monitor (Alcatel) and I have been told that it is possible to connect it to a CGA card (of course, giving CGA picture quality). The snag is that the VGA monitor comes with a 15-pin connector, and the CGA card has a 9-pin. I heard one story that it was possible to make a fairly simple connector for puting them together. Can anyone enlighten me as to which pin corresponds to which? Another story I heard was that this was impossible. Any comments? Thanks - John Beaven email: jlb@aipna.ed.uk.ac
psrc@pegasus.ATT.COM (Paul S. R. Chisholm) (11/23/89)
In article <1643@aipna.ed.ac.uk>, jlb@aipna.ed.ac.uk (John Beaven) writes: > I have recently got hold of a cheap monochrome VGA monitor (Alcatel) and I > have been told that it is possible to connect it to a CGA card (of course, > giving CGA picture quality). >... > Another story I heard was that this was impossible. That's the one I'd believe. CGA (and EGA) adapters send a "digital" signal; for every pixel, each "color" is on or off. (The definition of a color gets a little tricky; CGA has red, blue, green, and "intense", for four "colors", and 2**4 = 16 colors. EGA has reg, blue, green, intense red, intense blue, and intense green; six "colors", and a palette of 2**6 = 64 colors.) VGA color monitors have only three colors (red, blue, and green), but each color can be at 2**6 = 64 levels of intensity, for a palette that can choose between (2**6)**3 = 256K colors. I think VGA "monochrome" (really gray scale) monitors can display 2**6 shades of gray. You could use that to substitute for colors, but hardware to translate digital video to analog video would probably cost than a VGA board. Yes, there are multi-frequency monitors that can accept both analog and digital signals, beginning with the original MultiSync. I don't think that's what you've got. In my humble (yeah, right:-) opinion, the best way for you to use the monochrome VGA monitor would be to buy a VGA card. They're not that expensive, and you can trivially upgrade to color as soon as you can afford a color VGA monitor. > John Beaven, email: jlb@aipna.ed.uk.ac Paul S. R. Chisholm, AT&T Bell Laboratories att!pegasus!psrc, psrc@pegasus.att.com, AT&T Mail !psrchisholm I'm not speaking for the company, I'm just speaking my mind.